Portable devices often contain components requiring electrical power and in some cases the required electrical power can have relatively high voltage and current ratings. Receptacles have been designed to provide power to such portable devices. Reefer containers are one example of a portable device that requires power. Refrigerated shipping containers are used to ship goods throughout the world. Such refrigerated shipping containers can be transported on trains, trucks, and ships and the containers are often stationed at ports, warehouses, and distribution centers. While the refrigerated containers are located in these various modes of transportation and storage, they often need electrical power to operate the refrigeration unit of the container.
At times, a large number of such devices can be stored at one location, and so a network of receptacles is needed to provide power to each device. When these devices are moved (for example, to prepare for transportation), it can be difficult to identify the device and/or ensure that the receptacle is disconnected The receptacles used for reefer containers are relatively expensive, and damage can easily occur to these receptacles when a receptacle is still connected to a reefer container that is being moved. Also a number of facilities use automated crane systems that lack the intelligence to determine whether a reefer receptacle that is about to be moved is connected to a reefer receptacle.